Coating removal systems for optical fibers

Abstract

Coating removal systems for optical fibers are disclosed. Related methods and optical fibers processed with these methods and coating removal systems are also disclosed. An optical fiber includes a glass fiber, having a cladding and core, surrounded by a protective coating which does not contribute to the optical performance of the optical fiber. By removing the coating at an end portion of the optical fiber, the end portion may be precisely positioned and secured to enable reliable optical communications. A laser beam may be directed at the protective coating to remove the protective coating by one or more ablating, melting, vaporizing, and/or thermal decomposing processes. The optical fiber may also be optionally cleaved. In this manner, the coating may be efficiently removed while retaining at least fifty percent of the tensile strength of the optical fiber.

We claim: 
     
       1. A method of laser preparing an end portion of an optical fiber, comprising:
 emitting a laser beam from a laser; 
 removing at least a portion of a coating from an end portion of an optical fiber by:
 deflecting the laser beam at an angle theta repeatedly across an optical axis of the optical fiber with a control system to form at least two sets of laser scans; and 
 directing the laser beam with the control system to position respective scans of the at least two sets of laser scans to intersect the optical axis of the optical fiber at a plurality of radial positions; and 
 
 cleaving the end portion of the optical fiber by:
 removing at least a portion of the circumference of the optical fiber by deflecting the laser beam at an angle repeatedly across the optical axis of the optical fiber with the control system; and 
 directing the laser beam with the control system to position respective laser cleave scans of the at least two cleave sets of laser cleave scans to intersect the optical axis of the optical fiber at the plurality of radial positions. 
 
 
     
     
       2. The method of  claim 1 , wherein the at least two sets of laser scans provide a uniform or substantially uniform cumulative energy intensity incident around the circumference of the optical fiber. 
     
     
       3. The method of  claim 1 , further comprising maintaining the laser stationary with respect to the optical fiber during the removing the at least the portion of the coating. 
     
     
       4. The method of  claim 1 , wherein the directing the laser beam to position the at least two sets of laser scans comprises directing the laser beam to at least one reflector to deflect the laser beam to position the respective scans of at least one of the at least two sets of laser scans to intersect the optical axis of the optical fiber at one or more of the plurality of radial positions. 
     
     
       5. The method of  claim 1 , further comprising maintaining the laser stationary with respect to the optical fiber during the cleaving the end portion of the optical fiber. 
     
     
       6. The method of  claim 1 , wherein the directing the laser beam to position the at least two cleave sets of laser cleave scans comprises directing the laser beam to at least one reflector to deflect the laser beam to position the respective laser cleave scans of at least one of the at least two cleave sets of laser cleave scans to intersect the optical axis of the optical fiber at one or more of the plurality of radial positions. 
     
     
       7. The method of  claim 1 , wherein the deflecting the laser beam with the control system includes deflecting the laser beam at two different spot sizes while forming at least one of the at least two sets of laser scans. 
     
     
       8. The method of  claim 1 , wherein the angle theta is in a range from forty-five (45) degrees to ninety (90) degrees relative to the optical axis of the optical fiber. 
     
     
       9. The method of  claim 1 , further comprising changing a spot size of the laser beam to form the at least two sets of laser scans for a subsequent pass of the laser beam. 
     
     
       10. The method of  claim 1 , further comprising applying a tension to the optical fiber between one (1) percent and fifty (50) percent of a tensile strength of the optical fiber with a tension generator. 
     
     
       11. A method of laser preparing an end portion of an optical fiber, comprising:
 emitting a laser beam from a laser; and 
 removing at least a portion of a coating from an end portion of an optical fiber by:
 deflecting the laser beam at an angle theta repeatedly across an optical axis of the optical fiber with a control system to form at least two sets of laser scans, wherein the deflecting with the control system; 
 directing the laser beam with the control system to position respective scans of the at least two sets of laser scans to intersect the optical axis of the optical fiber at a plurality of radial positions; and 
 changing a spot size of the laser beam to form the at least two sets of laser scans for a subsequent pass of the laser beam. 
 
 
     
     
       12. The method of  claim 11 , wherein changing the spot size of the laser beam comprises increasing the spot size of the laser beam to form the at least two sets of laser scans for the subsequent pass of the laser beam. 
     
     
       13. The method of  claim 12 , further comprising increasing a focal length of the laser beam to form the at least two sets of laser scans for the subsequent pass of the laser beam. 
     
     
       14. The method of  claim 11 , further comprising changing one of a power, power density, power distribution, and wavelength of the laser beam to form the at least two sets of laser scans for the subsequent pass of the laser beam. 
     
     
       15. The method of  claim 11 , further comprising forming a portion of each of the at least two sets of laser scans before completely forming any set of the at least two sets of laser scans. 
     
     
       16. The method of  claim 11 , wherein the at least two sets of laser scans provide a uniform or substantially uniform cumulative energy intensity incident around the circumference of the optical fiber. 
     
     
       17. The method of  claim 11 , wherein the directing the laser beam to position the at least two sets of laser scans comprises directing the laser beam to at least one reflector to deflect the laser beam to position the respective scans of at least one of the at least two sets of laser scans to intersect the optical axis of the optical fiber at one or more of the plurality of radial positions. 
     
     
       18. The method of  claim 11 , wherein the deflecting the laser beam with the control system includes deflecting the laser beam at two different spot sizes while forming at least one of the at least two sets of laser scans. 
     
     
       19. The method of  claim 11 , wherein the angle theta is in a range from forty five (45) degrees to ninety (90) degrees relative to the optical axis of the optical fiber. 
     
     
       20. The method of  claim 11 , further comprising applying a tension to the optical fiber between one (1) percent and fifty (50) percent of a tensile strength of the optical fiber with a tension generator.